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slicot_mc01td


Checking stability of a given real polynomial.


Syntax


[DP_OUT, STABLE, NZ, IWARN, INFO] = slicot_mc01td(DICO, DP_IN, P)

Input argument


DICO

Indicates whether the stability test to be applied to P(x) is in the continuous-time or discrete-time case as follows: = 'C': Continuous-time case; = 'D': Discrete-time case.

DP_IN

The degree of the polynomial P(x).

P

This array must contain the coefficients of P(x) in increasing powers of x.

Output argument


DP_OUT

if P(DP+1) = 0.0 on entry, then DP contains the index of the highest power of x for which P(DP+1) != 0.0.

STABLE

Contains the value int32(1) if P(x) is stable and the value int32(0) otherwise.

NZ

If INFO = 0, contains the number of unstable zeros - that is, the number of zeros of P(x) in the right half-plane if DICO = 'C' or the number of zeros of P(x) outside the unit circle if DICO = 'D'.

IWARN

= 0: no warning;

INFO

= 0: successful exit; = 1: if on entry, P(x) is the zero polynomial;= 2: if the polynomial P(x) is most probably unstable.

Description


To determine whether or not a given polynomial P(x) with real coefficients is stable, either in the continuous-time or discrete-time case.

A polynomial is said to be stable in the continuous-time case if all its zeros lie in the left half-plane, and stable in the discrete-time case if all its zeros lie inside the unit circle.

Used function(s)


MC01TD

Bibliography


http://slicot.org/objects/software/shared/doc/MC01TD.html

Example


DICO = 'C';
DP_IN = 4;
P = [2.0  0.0  1.0  -1.0  1.0];
[DP, STABLE, NZ, IWARN, INFO] = slicot_mc01td(DICO, DP_IN, P)

History


Version Description
1.0.0 initial version

Author


SLICOT Documentation

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